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Newbie here! Need your collective wisdom on a proper crossover...

Hello all! I'm new to this forum, but not too unfamiliar with JBL, Altec, etc. I know I'll have plenty of questions as time goes on, but for now I'd like some ideas for an electronic crossover. I am in the process of building a "music room" where I can play guitar, etc. I have a pair of small monitors that I would like to add a subwoofer to. For now I'd like to buy a crossover and use a pair of D140's that I have for the low end (I know, not ideal, but I have to build the system up gradually to keep the boss (wife) happy). I used to have a Crown VFX-2A , but it's long gone. I have seen them on EvilBay, but I was wondering if I couldn't do better with something a little more current (better phase response?). I've looked at dbx, Rane, Behringer, etc. Ideally, I'd like to find one that has separate high and low pass frequency adjustments like the Crown used to have (for setting assymetrical crossover points). I have not had any success finding (at a reasonable price) anything like the Crown, except for Behringer's least expensive unit that has a separate subwoofer out and crossover adjustment.

I also have a pair of Altec 511B horns with LE175's that I'll eventually use with the woofers. Any suggestions for something to shoot for eventually in the way of bass drivers? Drivers that could work as subwoofers for now, and part of a integrated system later. I'm open for suggestions!

"I also have a pair of Altec 511B horns with LE175's that I'll eventually use with the woofers. Any suggestions for something to shoot for eventually in the way of bass drivers? Drivers that could work as subwoofers for now, and part of a integrated system later. I'm open for suggestions!"

I would look at 2235's as a driver that would fit your needs. Recones are a whopping $118 and you have a decent selection of frames to choose from for the reccone. You could buy used but this way you know what you are getting and it should run you less or even. Sensitivity is not that high at 93db but it is one nice woofer. Need some room for them around 5 cubic Ft.

Crossovers I can't help you much I use M553/M553 24db LR and they work great. Do not have the flexability you want but can be Ebayed very easilly at a decent price.

Re: Newbie here!

Originally posted by David Dryden Hello all! I'm new to this forum, but not too unfamiliar with JBL, Altec, etc. I know I'll have plenty of questions as time goes on, but for now I'd like some ideas for an electronic crossover. I am in the process of building a "music room" where I can play guitar, etc. .
I also have a pair of Altec 511B horns with LE175's that I'll eventually use with the woofers. Any suggestions for something to shoot for eventually in the way of bass drivers? Drivers that could work as subwoofers for now, and part of a integrated system later. I'm open for suggestions!

David

Hi David,

welcome to the forum.......

If you like to play guitar over the system...I cannot give my vote for the 2235 ......too soft....I think you need a very dry bass with a low frequency of 40Hz fres.
I f you need a monitor system as a multipurpose system with your 511 and LE 175 then its ok also with the 2235. But please pay attention to hook the LE 175 not under 700 Hz.

Electronic Crossover:
I use the Rane AC 23 and its a fine network with separate frequency adjust for the channels.

regards
HP

Please help us save more info about the vintage systems. Let us register your speakers and drivers.

Thanks for the replies! I'd like to clarify things a bit as I was typing my initial post at work and got side-tracked mid-stream. What I'm working towards is a system that is capable of quality playback at "live" sound pressure levels. Not ear bleed, (I'm 42, nothin' could make my bleed ears anymore anyway!), but loud enough that I can crank up my guitar and play along like I'm in the middle of the band. Of course, I know JBL is perfectly suited to the task, but I don't know which drivers would be the best for my application. I'm thinking that one 18" would do the job, but since I'd eventually like to have a pair to match up with the horns I already have, a pair of 15's would probably be best. I wouldn't be playing my guitar through the system necessarily as I have a couple of guitar amps that I use (a Line 6 and an old Fender Showman - guess where the D140's came from? ), but my wife's keyboard would probably be run directly into the system through the mixer.

I used to have a biamped setup using the LE175's, 511B horns, and a pair of 15 inch woofers from a manufacturer that I'm embarassed to mention. The system was driven off the Crown VFX-2A crossover, with a solid state amp on the low end and a McIntosh MC225 tube amp (which I still have!) driving the horns. Nice and smooth top end, just not quite high enough. I'd like to improve on that system by getting the bottom end right and eventually either adding a set of tweeters or replacing the LE175's altogether.

As far as the crossover goes, am I being too picky looking for a unit with separate high and low crossover point adjustments? I guess I'm just used to having that capability as a tool in lieu of using an EQ to tweek things a bit (I'm not fond of the idea of using EQ as a "fix-all"). Keep the ideas coming! Thanks!

My response to the objection HP bring up is: Use the 2235 kit in a recone, but DO NOT use the mass ring... ie, make a 2234. THAT should have NO PROBLEM mating up with a 511/LE175 horn setup! JBL uses them up to 1000 Hz, the 511 can go about an octave below that. With that, you should be able to easily get bass down to 40 Hz. And, if later, you want to use them as subs, simply remove the dustcap, glue in the mass ring, put on some new dustcaps and voila... instant 2235...

David,
If you liked the Crown VFX-2, why not get another off eBay? There are great crossovers, work at 18dB/ and are highly thought of here. The Rane AC22 is a good unit too.
You can use your Altec horns, JBL compression drivers and maybe even your D140Fs, but you'll have to do a lot of work getting these in cabinets, and balancing these to sound good together.

Want you would really be happy with is a pair of JBL 4333s. These come up on eBay from time to time. The advantage of using these vintage studio monitors is that they have been designed to be reasonably flat and kick pretty well in a small studio situation. You can run these full rage with a stereo amp (150 wpc min.) or bi-amp them, using an active crossover and 2 stereo power amps, and have a very nice high level playback set-up.

4333's eh? Hmmm. For some reason, that reminds me of how I used to lust after the L112's back in the early-mid 80's. Great sounding speaker that could also play loud enough to make any rock-n-roller happy. You wouldn't be planning on selling yours at some point would you?

I guess I need to really take a look at my music room and evaluate the layout. The room is kinda unusual in that it's the upper-most floor in our house, which is a tri-level. The room is going to serve as both a music room and a guest bedroom (sleeper sofa). The room is 19' long by 11 1/2' wide. The unusual part is that there is a knee wall on both long sides of the room that is around 5' tall, then the ceiling slopes at about 45 degrees, then is flat. The floors are hardwood, and the room has a nice sound to it. I've actually given thought to building a pair of niches in the knee walls to house a pair of large format monitors (15's, Altec horns, etc.). Because the room is so narrow, I'm not sure if that would work or not.

At any rate, I apoligize if I seem to ramble on Guess I'm kinda excited about the whole idea of finally getting started on our room.

I plan to release details of a discrete adjustable active crossover on the forum in a month or so.

If you are looking for very low noise and distortion with a fair degree of flexibility this could fit the bill.

On of the main issues about active crossovers is that while they are a convenient means of creating a crossover for a system you have in mind they are only a tool in the means to an end.

That is they do not ideally tailor the voltage drive to the components to acheive a perfectly flat amplitude response unless you have suitable measurement set and have the means to trim the active RC elements.

This is in part "why" many attempts to bi amp and tri amp meet with disppointing results. Yes it will sound clean and tight but the system may not appear as coherent as the original passive crossover which was made to measure.

Thanks Ian. I'm still watching a couple of Crowns on EvilBay. I am debating on whether to go with one of those, or purchase a new unit. Behringer makes a decent looking unit that has some of the flexibility that I'm looking for. DBX also makes a unit that is designed for studio use that not only has multiple crossover configurations, but time alignment (good for horn-woofer relationship), parametric and graphic EQ, etc. Neat unit, but as I mentioned before, a little spendy. I'd be interested in your project when you're done!

Due to all the excitement over the Sub1500 pn this board, I'm going to change direction a little bit and buy a pair. They won't fit into my ultimate music room system, but along with an electronic crossover, will work well with the small monitors that I'm currently using. Eventually, the Sub1500's will become part of the family room theater system. I like Tom's suggestion of the 4333's for the music room. A large format studio system. Accurate, but capable of decent volume. Now, all I gotta do is sell my LE175's, the Altec 511b's, my two vintage tube Altec mixers, and anything else that isn't nailed down . Then maybe, just maybe I'll be able to buy a pair (IF I can find a pair for sale that is). For now, I'm off to contribute to Parts Express' subwoofer fund!

Will the JBL DSC260 function similar to the M553 as far as crossovers go? From the specs, it looks like it, but I assume they're some type of digital crossover compared to analog? 'Any opinion on if this has any perceptible effect on the sound?

The M552/553 are analog so no delay and they don't have anyway near the flexability of a DSC260. I have no experience the the DSC260 but it looks very flexible just wonder about the a/d d/a conversion.

Originally posted by Robh3606 The M552/553 are analog so no delay and they don't have anyway near the flexability of a DSC260. I have no experience the the DSC260 but it looks very flexible just wonder about the a/d d/a conversion.

Rob

Well, 'hope to find out before long. I just picked up a DSC260 (A?) on eBay. I only saw it about 5 minutes before the auction ended, so 'had to make a snap decision...